And for multiple monitors I ditched their bases for a single dual monitor stand as my desk is also quite narrow - two stands were not quite fitting - and monitors do overhang on both sides of desk. I have seen modular stands where you can get more than one layer of monitors that are going through a hole in a desk. I also actually have still working but badly burned out 24'' that is on the floor waiting for emergencies and not used anymore as my stand is only 2 monitor capable - otherwise I would use it as well - never enough desktop estate
As for ultrawide - no experience
seen one IRL on my Director's desk, and have mixed feelings. Can see benefits of it for sure if you're in market for new monitor or previous don't have options you want, on other side i have several input devices to my monitors and very often watch TV on second monitor while doing stuff in single monitor configuration on other monitor..
Window scalling - whatever float your boat here, if your software does good job on this front then go for it - 1 cable set instead of 2 or more at back of desk is also not something to forget..
For the OP:
I have best of both worlds personally - two 27'' monitors, one is 4k@60Hz for graphical fidelity oriented tasks and for games like Cities Skyline and Anno 1800, second is 1440p 240Hz refresh for good GUI experience without window scaling things, and for FPS gaming.
There's also one factor in play - your health. Older monitor technologis are - well - old, and new monitor have impact on your eyes. You plan to WFH - that's a big thing to consider as well.